open FILE, "<:utf8", "C:\\Documents and Settings\\R19338\\Desktop\\gerry_weber_de_105_1227.xml";
open WFILE, ">:utf8", "C:\\Documents and Settings\\R19338\\Desktop\\perl.txt";

my $file_contents = '';

while (<FILE>) {
		$file_contents .= $_;
	}
while ($file_contents =~ /(<Product>.*?<\/Product>)/isg){
	$one_product = $1;
	if ($one_product =~ /(<ProductId>.*?<\/ProductId>).*?(<Size>.*<\/Size>)/isg) {
		print WFILE $1."\n".$2."\n\n";
	}
}